Unit doses of liquid products such as shampoo and hair conditioner are often placed in relatively thin, flat packages known as sachets. Such sachets are typically provided with water vapor barrier properties to prevent water loss from the product in the package over time. Sachets of this type are generally made using vertical forming, filling and sealing (VFFS) processes.
Current processes exist for vertical forming, filling and sealing, both intermittently and continuously. Vertical forming, filling and sealing (VFFS) processes typically employ one set of fill nozzles that are inserted in between two layers of material used to form the package. The nozzles must turn on and shut off after filling each package. For intermittent motion processes, filling occurs while the film or packaging material is in motion, and the film stops during the sealing process. Even for continuous processes, where all operations are performed on moving webs, rates become limited by the filling process. The ability to accurately dispense the desired amount of liquid in extremely short dispensing cycle times is needed.
Processes also exist for horizontal forming, filling, and sealing. Examples of horizontal forming, filling, and sealing processes are described in PCT Publication WO 2004/033301 A1, Smith, et al.; US. Patent Application Publication US 2005/0183394 A1; and EP 1 375 351 B1, Lauretis, et al. Some of such processes may involve thermoforming a portion of the packaging material.
The search for improved package forming processes and filling systems has, however, continued. In particular, there is a need for faster processes for producing sachets, especially sachets that comprise films made with vapor barriers that cannot be thermoformed without disrupting the vapor barrier.